blob.h

   1 /*
   2  * blob - library for generating/parsing tagged binary data
   3  *
   4  * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #ifndef _BLOB_H__
  20 #define _BLOB_H__
  21
  22 #include <stdbool.h>
  23 #include <stdlib.h>
  24 #include <stdint.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <errno.h>
  28
  29 #include "utils.h"
  30
  31 enum {
  32         BLOB_ATTR_UNSPEC,
  33         BLOB_ATTR_NESTED,
  34         BLOB_ATTR_BINARY,
  35         BLOB_ATTR_STRING,
  36         BLOB_ATTR_INT8,
  37         BLOB_ATTR_INT16,
  38         BLOB_ATTR_INT32,
  39         BLOB_ATTR_INT64,
  40         BLOB_ATTR_LAST
  41 };
  42
  43 #define BLOB_ATTR_ID_MASK  0xff000000
  44 #define BLOB_ATTR_ID_SHIFT 24
  45 #define BLOB_ATTR_LEN_MASK 0x00ffffff
  46 #define BLOB_ATTR_ALIGN    4
  47
  48 struct blob_attr {
  49         uint32_t id_len;
  50         char data[];
  51 } __packed;
  52
  53 struct blob_attr_info {
  54         unsigned int type;
  55         unsigned int minlen;
  56         unsigned int maxlen;
  57         bool (*validate)(const struct blob_attr_info *, struct blob_attr *);
  58 };
  59
  60 struct blob_buf {
  61         struct blob_attr *head;
  62         bool (*grow)(struct blob_buf *buf, int minlen);
  63         int buflen;
  64         void *buf;
  65 };
  66
  67 /*
  68  * blob_data: returns the data pointer for an attribute
  69  */
  70 static inline void *
  71 blob_data(const struct blob_attr *attr)
  72 {
  73         return (void *) attr->data;
  74 }
  75
  76 /*
  77  * blob_id: returns the id of an attribute
  78  */
  79 static inline unsigned int
  80 blob_id(const struct blob_attr *attr)
  81 {
  82         int id = (be32_to_cpu(attr->id_len) & BLOB_ATTR_ID_MASK) >> BLOB_ATTR_ID_SHIFT;
  83         return id;
  84 }
  85
  86 /*
  87  * blob_len: returns the length of the attribute's payload
  88  */
  89 static inline unsigned int
  90 blob_len(const struct blob_attr *attr)
  91 {
  92         return (be32_to_cpu(attr->id_len) & BLOB_ATTR_LEN_MASK) - sizeof(struct blob_attr);
  93 }
  94
  95 /*
  96  * blob_raw_len: returns the complete length of an attribute (including the header)
  97  */
  98 static inline unsigned int
  99 blob_raw_len(const struct blob_attr *attr)
 100 {
 101         return blob_len(attr) + sizeof(struct blob_attr);
 102 }
 103
 104 /*
 105  * blob_pad_len: returns the padded length of an attribute (including the header)
 106  */
 107 static inline unsigned int
 108 blob_pad_len(const struct blob_attr *attr)
 109 {
 110         int len = blob_raw_len(attr);
 111         len = (len + BLOB_ATTR_ALIGN - 1) & ~(BLOB_ATTR_ALIGN - 1);
 112         return len;
 113 }
 114
 115 static inline uint8_t
 116 blob_get_u8(const struct blob_attr *attr)
 117 {
 118         return *((uint8_t *) attr->data);
 119 }
 120
 121 static inline uint16_t
 122 blob_get_u16(const struct blob_attr *attr)
 123 {
 124         uint16_t *tmp = (uint16_t*)attr->data;
 125         return be16_to_cpu(*tmp);
 126 }
 127
 128 static inline uint32_t
 129 blob_get_u32(const struct blob_attr *attr)
 130 {
 131         uint32_t *tmp = (uint32_t*)attr->data;
 132         return be32_to_cpu(*tmp);
 133 }
 134
 135 static inline uint64_t
 136 blob_get_u64(const struct blob_attr *attr)
 137 {
 138         uint32_t *ptr = blob_data(attr);
 139         uint64_t tmp = ((uint64_t) be32_to_cpu(ptr[0])) << 32;
 140         tmp |= be32_to_cpu(ptr[1]);
 141         return tmp;
 142 }
 143
 144 static inline int8_t
 145 blob_get_int8(const struct blob_attr *attr)
 146 {
 147         return blob_get_u8(attr);
 148 }
 149
 150 static inline int16_t
 151 blob_get_int16(const struct blob_attr *attr)
 152 {
 153         return blob_get_u16(attr);
 154 }
 155
 156 static inline int32_t
 157 blob_get_int32(const struct blob_attr *attr)
 158 {
 159         return blob_get_u32(attr);
 160 }
 161
 162 static inline int64_t
 163 blob_get_int64(const struct blob_attr *attr)
 164 {
 165         return blob_get_u64(attr);
 166 }
 167
 168 static inline const char *
 169 blob_get_string(const struct blob_attr *attr)
 170 {
 171         return attr->data;
 172 }
 173
 174 static inline struct blob_attr *
 175 blob_next(const struct blob_attr *attr)
 176 {
 177         return (struct blob_attr *) ((char *) attr + blob_pad_len(attr));
 178 }
 179
 180 extern void blob_fill_pad(struct blob_attr *attr);
 181 extern void blob_set_raw_len(struct blob_attr *attr, unsigned int len);
 182 extern bool blob_attr_equal(const struct blob_attr *a1, const struct blob_attr *a2);
 183 extern int blob_buf_init(struct blob_buf *buf, int id);
 184 extern void blob_buf_free(struct blob_buf *buf);
 185 extern void blob_buf_grow(struct blob_buf *buf, int required);
 186 extern struct blob_attr *blob_new(struct blob_buf *buf, int id, int payload);
 187 extern void *blob_nest_start(struct blob_buf *buf, int id);
 188 extern void blob_nest_end(struct blob_buf *buf, void *cookie);
 189 extern struct blob_attr *blob_put(struct blob_buf *buf, int id, const void *ptr, int len);
 190 extern bool blob_check_type(const void *ptr, int len, int type);
 191 extern int blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_attr_info *info, int max);
 192 extern struct blob_attr *blob_memdup(struct blob_attr *attr);
 193
 194 static inline struct blob_attr *
 195 blob_put_string(struct blob_buf *buf, int id, const char *str)
 196 {
 197         return blob_put(buf, id, str, strlen(str) + 1);
 198 }
 199
 200 static inline struct blob_attr *
 201 blob_put_u8(struct blob_buf *buf, int id, uint8_t val)
 202 {
 203         return blob_put(buf, id, &val, sizeof(val));
 204 }
 205
 206 static inline struct blob_attr *
 207 blob_put_u16(struct blob_buf *buf, int id, uint16_t val)
 208 {
 209         val = cpu_to_be16(val);
 210         return blob_put(buf, id, &val, sizeof(val));
 211 }
 212
 213 static inline struct blob_attr *
 214 blob_put_u32(struct blob_buf *buf, int id, uint32_t val)
 215 {
 216         val = cpu_to_be32(val);
 217         return blob_put(buf, id, &val, sizeof(val));
 218 }
 219
 220 static inline struct blob_attr *
 221 blob_put_u64(struct blob_buf *buf, int id, uint64_t val)
 222 {
 223         val = cpu_to_be64(val);
 224         return blob_put(buf, id, &val, sizeof(val));
 225 }
 226
 227 #define blob_put_int8   blob_put_u8
 228 #define blob_put_int16  blob_put_u16
 229 #define blob_put_int32  blob_put_u32
 230 #define blob_put_int64  blob_put_u64
 231
 232 #define __blob_for_each_attr(pos, attr, rem) \
 233         for (pos = (void *) attr; \
 234              rem > 0 && (blob_pad_len(pos) <= rem) && \
 235              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 236              rem -= blob_pad_len(pos), pos = blob_next(pos))
 237
 238
 239 #define blob_for_each_attr(pos, attr, rem) \
 240         for (rem = attr ? blob_len(attr) : 0, \
 241              pos = attr ? blob_data(attr) : 0; \
 242              rem > 0 && (blob_pad_len(pos) <= rem) && \
 243              (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
 244              rem -= blob_pad_len(pos), pos = blob_next(pos))
 245
 246
 247 #endif